When Howltooth Creek enters the battlefield, sacrifice it unless you pay 1 life.
: Add or to your mana pool.
Put Howltooth Creek on top of your library: Add to your mana pool.
, , Sacrifice Howltooth Creek: Destroy target creature.
: Add 
or 
to your mana pool.
to your mana pool. 
, , Sacrifice Howltooth Creek: Destroy target creature.
